Patents Represented by Attorney, Agent or Law Firm Theresa A. Lober
  • Patent number: 5619368
    Abstract: An optical wavelength converter is provided that utilizes an optical interferometer configured to efficiently and rapidly shift the frequency of an optical signal and to automatically separate a pump signal from the optical signal and a frequency-shifted signal. The wavelength converter is configured with a signal port for accepting an input optical signal, of a first wavelength, to be processed for producing an output signal of a second wavelength, and a pump port for accepting a laser pump signal of a pump wavelength. An optical interferometer is connected to the signal and pump ports to separately receive the input signal from the signal port and a pump signal from the pump port and to inject each received signal independently into a nonlinear medium. In the nonlinear medium, the input and pump signals nonlinearly interact via a nonlinear optical property of the nonlinear medium to generate an output conjugate signal of a second wavelength.
    Type: Grant
    Filed: October 13, 1995
    Date of Patent: April 8, 1997
    Assignee: Massachusetts Inst. of Technology
    Inventor: Eric A. Swanson
  • Patent number: 5617434
    Abstract: A fiber laser for producing high energy ultrashort laser pulses, having a positive-dispersion fiber segment and a negative-dispersion fiber segment joined in series with the positive-dispersion fiber segment to form a laser cavity. With this configuration, soliton effects of laser pulse circulation in the cavity are suppressed and widths of laser pulses circulating in the cavity undergo large variations between a maximum laser pulse width and a minimum laser pulse width during one round trip through the cavity. The fiber laser also provides means for modelocking laser radiation in the laser cavity, means for providing laser radiation gain in the laser cavity, and means for extracting laser pulses from the laser cavity.
    Type: Grant
    Filed: April 22, 1996
    Date of Patent: April 1, 1997
    Assignee: Massachusetts Inst. of Technology
    Inventors: Kohichi R. Tamura, Erich P. Ippen, Hermann A. Haus, Lynn E. Nelson, Christopher R. Doerr
  • Patent number: 5553093
    Abstract: A laser resonant cavity defined by a set of reflective end elements positioned to together form a closed optical path, again medium positioned along the closed optical path, means for exciting the gain medium to produce a laser beam within the cavity, at least one focusing element positioned within the cavity in optical alignment with the gain medium, and a prism positioned as one of the end elements of the cavity and providing angular dispersion of the laser beam. The prism, end elements, gain medium, and focusing elements are positioned with respect to each other such that the resonant cavity supports a coexistence of several monochromatic laser modes, each mode having a distinct propagation axis. Propagation axes of modes having relatively longer wavelengths traverse more of the prism than propagation axes of modes having relatively shorter wavelengths, resulting in the addition of a negative component to the group velocity dispersion of the laser cavity.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: September 3, 1996
    Assignee: Massachusetts Institute of Technology
    Inventors: Mailini Ramaswamy, James G. Fujimoto
  • Patent number: 5511428
    Abstract: A sensor microstructure contact scheme is provided for making backside electrical, mechanical, fluidic, or other contact to mechanical microstructures. The contact scheme is applicable to pressure sensors, shear stress sensors, flow rate sensors, temperature sensors, resonant microactuators, and other microsensors and microactuators. The contact scheme provides a microelectromechanical sensor body and support structure for backside contact of the sensor body, and features a support wafer substrate having one or more through-wafer vias each with a lateral span on the dimension of microns and a span that is more narrow at the wafer front surface than at the wafer back surface. An insulating film covers a portion of the support wafer substrate and sidewalls of the vias--with the lateral via span at the front surface being open.
    Type: Grant
    Filed: June 10, 1994
    Date of Patent: April 30, 1996
    Assignee: Massachusetts Institute of Technology
    Inventors: Howard D. Goldberg, Martin A. Schmidt
  • Patent number: 5513194
    Abstract: A fiber laser for producing high energy ultrashort laser pulses, having a positive-dispersion fiber segment and a negative-dispersion fiber segment joined in series with the positive-dispersion fiber segment to form a laser cavity. With this configuration, soliton effects of laser pulse circulation in the cavity are suppressed and widths of laser pulses circulating in the cavity undergo large variations between a maximum laser pulse width and a minimum laser pulse width during one round trip through the cavity. The fiber laser also provides means for modelocking laser radiation in the laser cavity, means for providing laser radiation gain in the laser cavity, and means for extracting laser pulses from the laser cavity.
    Type: Grant
    Filed: April 7, 1995
    Date of Patent: April 30, 1996
    Assignee: Massachusetts Institute of Technology
    Inventors: Kohichi Tamura, Erich P. Ipen, Hermann S. Haus, Lynn E. Nelson, Christopher R. Doerr
  • Patent number: 5411654
    Abstract: For a condensed matter system containing a guest interstitial species such as hydrogen or its isotopes dissolved in the condensed matter host lattice, the invention provides tuning of the molecular orbital degeneracy of the host lattice to enhance the anharmonicity of the dissolved guest sublattice to achieve a large anharmonic displacement amplitude and a correspondingly small distance of closest approach of the guest nuclei. The tuned electron molecular orbital topology of the host lattice creates an energy state giving rise to degenerate sublattice orbitals related to the second nearest neighbors of the guest bonding orbitals. Thus, it is the nuclei of the guest sublattice that are set in anharmonic motion as a result of the orbital topology. This promotion of second nearest neighbor bonding between sublattice nuclei leads to enhanced interaction between nuclei of the sublattice.
    Type: Grant
    Filed: July 2, 1993
    Date of Patent: May 2, 1995
    Assignee: Massachusetts Institute of Technology
    Inventors: Brian S. Ahern, Keith H. Johnson, Harry R. Clark, Jr.